Third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture are able to support more sophisticated services than simple voice and messaging services offered by previous generations of mobile telecommunication systems.
For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy third and fourth generation networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to increase rapidly.
The anticipated widespread deployment of third and fourth generation networks has led to the parallel development of a class of devices and applications which, rather than taking advantage of the high data rates available, instead take advantage of the robust radio interface and increasing ubiquity of the coverage area. Examples include so-called machine type communication (MTC) applications, which are typified by semi-autonomous or autonomous wireless communication devices (i.e. MTC devices) communicating small amounts of data on a relatively infrequent basis. Examples include so-called smart meters which, for example, are located in a customers house and periodically transmit information back to a central MTC server data relating to the customers consumption of a utility such as gas, water, electricity and so on. Such MTC devices may therefore communicate using a different network to the conventional terminals where the networks can be more adapted to the needs of MTC devices or conventional terminals. As each of MTC devices and conventional devices then use a different autonomous network, some information may be duplicated in each network.
Also, systems where a terminal may be connected to more than one carrier are starting to emerge. For example a terminal may communicate with a base station via two separate carriers so that it can increase its throughput. The terminal then uses each of the two carriers in a manner similar to a single-carrier situation. Other terminals may be connected to only one of these two carriers and, in effect, these carriers are not exclusive to terminals using more than one carrier. Each of these carriers therefore has to be able to function autonomously from the other carriers. For example, the carrier has to provide the carrier control information and any carrier-management related information relevant to the terminals so that it is available to the terminals using this carrier only.
In situations where more than one carrier is provided, each of these carriers are usually expected to function autonomously from each other and they therefore comprise their own carrier-management information and any other broadcasted information or data so that a terminal connected to this carrier only can always be given access to the information or data in the carrier. In some situations, in order to ensure that each of these carriers may be autonomously used by a terminal, there may be partial or complete duplication of such data in two or more carriers.